1. Field of the Invention
The present invention relates generally to powered edge trimmer devices and, more particularly, to edge trimmer devices attached to power lawnmowers.
2. Description of the Prior Art
When grass is cut, it is often desirable to trim edges of sidewalks, driveways, and the like. Currently, three types of edge trimmers are known in the prior art: a first has manually operated blades; a second has a power-driven blade in a separate and distinct edge trimmer device; and a third employs an edge trimmer device in conjunction with a power-driven lawnmower. With particular attention being paid to the edge trimmers associated with power-driven lawnmowers, throughout the years, a number of innovations have been developed, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 3,686,839; 3,789,591; 4,378,668; 4,551,967; and 4,718,221. More specifically, each of U.S. Pat. Nos. 3,686,839 and 4,551,967 discloses an edge trimmer associated with a lawnmower wherein the edge trimmer is powered by the lawnmower by using a drive belt. It is well known that drive belts stretch and crack with age. Moreover, the drive belt must be used with accompanying pulleys. To eliminate the complexities associated with the use of drive belts, it would be desirable if a lawnmower-attached edge trimmer device could operate without using a drive belt.
U.S. Pat. No. 3,789,591 discloses a power lawnmower having an auxiliary flexible drive shaft for an edger head. A separate and distinct drive disk is provided above the lawnmower blade on the drive shaft. A spring-biased driven friction wheel is selectively placed in frictional contact with the drive disk. The friction wheel itself is part of an assembly which is pivotally connected to the body of the lawnmower. To avoid the use of a spring (which may fatigue) and to avoid the use of a pivoted connection (which may need regular lubrication), it would be desirable if a lawnmower-powered edge trimmer does not operate by using a spring or a pivoted connection assembly.
U.S. Pat. No. 4,378,668 discloses a lawnmower-powered edge trimmer which employs a plurality of whip blades which are kept in constant motion even when the blades are not being used for trimming. When retractable guards are retracted, the whip blades are permitted to extend outward to be used for trimming. When the retractable guards are returned to their original positions, the whip blades are once again prevented from trimming. It is wasteful of energy to keep whip blades in constant rotation even when they are not being used for trimming. For this reason, it would be desirable if a lawnmower-powered edge trimmer does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming.
U.S. Pat. No. 4,718,221 an edger and trimmer that is carried by a lawnmower body, but the lawnmower engine does not power the cutting action of the edger and trimmer. More specifically, a cutting disk that is selectively raised or lowered by an operator. When the cutting disk is raised, it does not contact the ground. However, when the cutting disk is lowered, the cutting disk contacts the ground and trims the grass as a result of the lawnmower being pushed along the ground by an operator. No power is tapped from the lawnmower engine to be sent to the cutting blades. Some grass will not readily be cut by a relatively slow moving cutting disk as described above that is not powered by the lawnmower engine.
Still other features would be desirable in a lawnmower-attached edge trimmer apparatus. For example, there are many lawnmowers currently in use that do not contain edge trimmer features. In this respect, it would be desirable if a conventional lawnmower could be retrofitted to provide a lawnmower-powered edge trimmer. With respect to retrofitting, conventional lawnmowers come in a variety of sizes. More specifically, the circumferences of the housings for the cutting blades of lawnmowers may differ from one lawnmower to another. In this respect, it would be desirable if a lawnmower-attached edge trimmer apparatus that is retrofitted to a lawnmower could be adjusted to a variety of sizes of lawnmower housings.
Thus, while the foregoing body of prior art indicates it to be well known to use lawnmower-attached edge trimmer devices, the prior art described above does not teach or suggest a lawnmower-attached edge trimmer apparatus which has the following combination of desirable features: (1) does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming; (2) can be retrofitted to a conventional lawnmower; (3) can be adjusted to a variety of sizes of lawnmower housings; (4) has a manually controlable connect/disconnect between the attached auxilliary trimmer apparatus and the main lawnmower drive; and (5) includes easy adjustment of the angular orientation of the attached trimmer cutting blades or filaments to conveniently control the width of cut of the auxilliary cutting apparatus. The foregoing desired characteristics are provided by the unique lawnmower-attached edge trimmer apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.
To achieve the foregoing and other advantages, the present invention, briefly described, provides an edge trimmer apparatus attached to a lawnmower which has a drive shaft and which has a blade housing having a lower housing wall, wherein the drive shaft rotates around a longitudinal axis. The lawnmower-attached edge trimmer apparatus includes a combined flywheel and blade assembly which includes a flywheel portion connected to the lawnmower drive shaft. A plurality of blade members extend radially out from the flywheel portion. An attachment assembly is connected onto portions of the lower housing wall of the blade housing. A trimmer assembly is attached to the attachment assembly. The trimmer assembly includes a bearing portion connected to the attachment assembly, a rotatable shaft assembly received by the bearing portion, a driven wheel connected to a proximal end of the rotatable shaft assembly, and a trimmer blade connected to a distal end of the rotatable shaft assembly. A protective shroud is connected to the attachment assembly.
The rotatable shaft assembly is adjustable along its longitudinal axis. More specifically, the rotatable shaft assembly includes a first segment which carries the driven wheel. A second segment of the rotatable shaft assembly carries the trimmer blade. A length-adjustment assembly is connected between the first segment and the second segment.
The blade members lie in a blade plane. The flywheel portion includes a driving surface which lies in a driving plane. The driving plane is spaced apart from the blade plane longitudinally along the longitudinal axis by a clearance distance.
The attachment assembly includes a first clamp assembly attachable to a first portion of the lower housing wall of the blade housing. The first clamp assembly includes a first U-shaped bracket member which slips over a portion of the lower housing wall of the blade housing. A set of nuts and bolts connect the first U-shaped bracket member to the lower housing wall. The first U-shaped bracket member includes a pair of bearing-receiving apertures for receiving the bearing portion of the rotatable shaft assembly.
The attachment assembly can further include a second clamp assembly attached to a second portion of the lower housing wall of the blade housing. An adjustable-length strut assembly can be connected between the first clamp assembly. The second clamp assembly includes a second U-shaped bracket member which slips over a portion of the lower housing wall of the blade housing. A set of nuts and bolts for connect the second U-shaped bracket member to the lower housing wall.
The adjustable-length strut assembly includes a pair of first telescopic members connected to the first clamp assembly and a pair of second telescopic members connected to the second clamp assembly.
In accordance with additional embodiments of the invention, the edge trimmer apparatus includes a drive member supported by the drive shaft above the blade housing. A power transmission assembly is connected to the drive member and is supported by the blade housing. A trimmer blade unit is supported by and driven by the power transmission assembly.
In accordance with another embodiment of the invention, the drive member can be a drive pulley supported by the drive shaft. The power transmission assembly includes a gear-containing transmission unit supported by the lower housing wall of the blade housing. An endless belt is connected between the drive pulley and the gear-containing transmission unit, and a trimmer blade unit is supported by and driven by the gear-containing transmission unit. The gear-containing transmission unit includes a first bevel gear assembly connected to the lower housing wall of the blade housing. The first bevel gear assembly supports and drives the trimmer blade unit. A pulley/gear transmission support bracket is supported by the first bevel gear assembly. The pulley/gear transmission support bracket includes a vertical first bracket portion and a horizontal second bracket portion. The vertical first bracket portion is connected to the first bevel gear assembly. A driven pulley is supported in an overhead manner by the horizontal second bracket portion of the pulley/gear transmission support bracket. A gear-driving shaft is connected to the driven pulley, and a second bevel gear assembly is connected to the gear-driving shaft. The second bevel gear assembly is enmeshed with the first bevel gear assembly.
The first bevel gear assembly includes a bearing portion connected to the lower housing wall of the blade housing. A gear shaft portion is retained by the bearing portion and supports the trimmer blade unit. A first bevel gear is supported by the gear shaft portion. A protective shroud is connected to the vertical first bracket portion of the pulley/gear transmission support bracket.
In accordance with another embodiment of the invention, the drive member can be a ring gear. In this case, the power transmission assembly includes a longitudinal drive shaft assembly supported by the blade housing. The longitudinal drive shaft assembly includes a geared end enmeshed with the ring gear. A shaft portion extends horizontally from the geared end, and a coupler end is located at a distal end of the shaft portion. The coupler end is connected to the trimmer blade unit. A bearing jacket jackets the shaft portion of the longitudinal drive shaft assembly. Jacket-support brackets support the bearing jacket and are supported by the blade housing. The coupler end of the longitudinal drive shaft assembly includes a well portion.
In accordance with another embodiment of the invention, the trimmer blade unit includes a blade, a rigid key-carrying portion is connected to the blade, and a key portion is received in the well portion of the longitudinal drive shaft assembly. The rigid key-carrying portion includes external threads. A threaded lock nut is supported by the bearing jacket and engages the external threads of the rigid key-carrying portion of the trimmer blade unit for locking the longitudinal drive shaft assembly to the trimmer blade unit. A spring assembly can be placed between the trimmer blade unit and the longitudinal drive shaft assembly for urging the trimmer blade unit toward the longitudinal drive shaft assembly.
In accordance with another embodiment of the invention, the trimmer blade unit includes a blade, a blade-retaining shaft supports the blade, and a shaft-bearing assembly supports the blade-retaining shaft. A flexible power cable assembly is connected to the blade-retaining shaft for connection to the longitudinal drive shaft assembly. A hinged trimmer-unit-support assembly is connected to the lower housing wall of the blade housing and supports the shaft-bearing assembly. The blade lies in a blade plane.
The flexible power cable assembly includes a proximal end connected to the blade-retaining shaft. A flexible cable portion is connected to the proximal end, and a key portion is connected to the flexible cable portion. The key portion is received in the well portion of the longitudinal drive shaft assembly. The longitudinal length of the well portion of the shaft portion of the longitudinal drive shaft assembly is equal to or greater than the combined length of the key portion and the flexible cable portion of the flexible power cable assembly.
The hinged trimmer-unit-support assembly includes a fixed support member connected to the lower housing wall of the blade housing, a movable support member that supports the shaft-bearing assembly, and a hinge pin connecting the fixed support member and the movable support member together, whereby the movable support member can be rotated around the fixed support member. An orientation lock is connected between the fixed support member and the movable support member for locking the fixed support member and the movable support member at a selected angular orientation.
In accordance with yet another embodiment of the invention, a manually actuatable control cable is attached through suitable means to the drive shaft supported on the lawnmower housing between the drive wheel and the auxiliary trimmer apparatus to control engagement and disengagement thereof. Additionally, angular orientation adjustment means for the auxiliary trimmer assembly relative to the main rotation shaft axis of the lawnmower are provided to assure precise control of the width of cut afforded by the auxiliary trimmer apparatus.
The above brief description sets forth rather broadly the more important features of the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contributions to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will be for the subject matter of the claims appended hereto.
In this respect, before explaining several preferred embodiments of the invention in detail, it is understood that the invention is not limited in its application to the details of the construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood, that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which disclosure is based, may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
It is therefore an object of the present invention to provide a new and improved lawnmower-attached edge trimmer apparatus which has all of the advantages of the prior art and none of the disadvantages.
It is another object of the present invention to provide a new and improved lawnmower-attached edge trimmer apparatus which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved lawnmower-attached edge trimmer apparatus which is of durable and reliable construction.
An even further object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such lawnmower-attached edge trimmer apparatus available to the buying public.
Still yet a further object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which can operate without using a drive belt.
Still another object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus that does not operate by using a spring or a pivoted connection assembly.
Yet another object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming.
Even another object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus that can be retrofitted to a conventional lawnmower.
Still a further object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which can be adjusted to a variety of sizes of lawnmower housings.
These together with still other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.